"rpdugan" I just came upon your post and it's been posted since November, but if your seeking a answer, I just acquired a MR88 from my late friends estate and called McIntosh Labs and spoke with Chuck regarding your very question. He mention to get the Audovox XHD2HI XM home tuner which I ordered from Amazon. I just hoping once I get it I don't have a firmware issue that's mentioned in this thread. My friend had purchased the unit new in December 2013 so it may have the most recent firmware. First night listening, unit sounds great on some local jazz HD channels. I will also be ordering a remote for it, Chuck at McIntosh say it uses a HR085 Remote. Enjoy your MR88!